Apple has updated its App Store Marketing Guidelines and is now advising developers against using images of the gold iPhone 5s in their marketing materials. According to the new rules, apps carried on the App Store can’t feature screenshots on gold iPhone 5s devices nor can such shots be used in other materials used for marketing communications.

Developers should “feature only the most current Apple products”, the updated guideline notes, specifically mentioning the following finishes or colors: iPhone 5s in silver or space gray, iPhone 5c in white or blue, iPad Air in silver or space gray and iPad mini in silver or space gray…

The change in Apple’s App Store Marketing Guidelines was first reported on by Eric Slivka of MacRumors this morning. In addition to gold, Apple has also excluded yellow, green and red iPhone 5c images from the list of colors allowed in photography and video marketing materials.

The new rules arrive hot on the heels off yesterday’s survey which revealed that U.S. customers, by and large, prefer their iPhone 5c units in blue and white, while space grey being the most popular color preference for those in the market for an iPhone 5s.

Apple recently changed the guidelines to allow developers to, for the first time in many years, use images of devices other than black in their marketing communications, though many developers hadn’t adhered to the previous rules at all.

Apple apparently wants to retain exclusive rights to using gold iPhone shots in marketing materials and ads. A good example is the first iPhone 5s television commercial, titled ‘Metal Mastered’ and included below, which exclusively focuses on the new gold colorway.

Moreover, a pair of iPhone 5s print ads (here and here) feature a gold iPhone 5s set against a goldish background. In the meantime, the gold iPhone 5s is something of a unicorn: everyone’s talking about it, but it’s in extremely short supply and virtually impossible to buy in many Apple and carrier retail stores worldwide.

Another possible explanation: as white and blue are easy to depict on screen and in print, the company may have decided that red, green, yellow and gold may suffer from getting coloring correct, prompting them to exclude these colors on the ground of reproduction issues.